1. Field of the Invention
The present invention relates to the separation of isotopes from a gaseous mixture by means of a rotary chamber such as, for example, a centrifuge reactor having means therein to radiate the gaseous mixture with a wave length or frequency characteristic of the absorption of a particular isotope of the atomic or molecular gaseous mixture so as to induce a photochemical reaction of the desired isotope.
2. Description of the Prior Art
The separation of isotopes by spinning highly volatile gas at fairly high speeds is known. Such separation is known in the art as the gas-centrifuge method. In the typical centrifuge reactor a gaseous compound is subjected to spinning at very high rotational speeds within a cylindrical rotor, causing the gas particles containing the heavier isotope to be thrust against the wall of the rotor. In particular, the rotation of the rotor drives the gas radially against the wall of the rotor such that a substantial portion of the center of the cylinder is under vacuum or close to it, even though no pump is employed. The gas particles tend to concentrate at the peripheral wall of the rotor. A weak vertical circulation is effected by, for example, providing a bottom scoop within the rotor which functions in combination with temperature differences at the top and bottom caps for the rotor to cause vertically axial movement of the gas at the peripheral wall of the rotor, in a known manner. A top scoop is also provided to scoop the desired particles.
The foregoing type of centrifuge reactor is well known in the art. Representative of such a reactor is discussed in an article entitled "The Gas Centrifuge" by Donald R. Olander, (Scientific American, Volume 239, No. 2, August 1978). The reactor discussed in the Olander article is particularly useful in enrichment by increasing the concentration of one isotope relative to another. The use of such a reactor is very economical, a large separation factor and sufficient throughput being provided. However, the scoop provided in a typical centrifuge reactor is of a finite size which means that it is usually not possible to scoop a single isotope from a distribution of isotopes that are enriched. Therefore, regardless of the favorable economics, in applications where only one of several isotopes is needed, centrifugal reactors heretofore in use have not been particularly useful.
Another known means for the separation of isotopes involves photochemical separation. Examples of photochemical separation can be found in U.S. Pat. Nos. 2,713,025 to Billings; 3,673,406 to Wief et al.; 3,983,019 to Botter nee Bergheaud et al.; 3,996,120 to Freund et al.; and 4,096,046 to Niemann. These patents are of interest in that they describe various apparatuses and methods for use in photochemical isotope separation using one form or another of a lamp for irradiation of a gas stream to effect the separation. The photochemical isotope separation process is known to be useful in those instances where photons from a particular radiation source excite only one isotope. The apparatus used in such a process is useful in obtaining a single isotope from a distribution of isotopes without substantially altering the composition of the other isotopes in the distribution. One disadvantage of such photochemical isotope separation is that due to deposits containing enriched material, eventually the entry window for the photons becomes foggy unless some means is provided to prevent such a buildup. A similar fogginess results from the use of a lamp if the envelope of the lamp is in contact with the chemical during the photochemical separation process. When the lamp envelope or entry window becomes foggy, it is necessary to stop the reactor or activate some form of scraper or the like to clean the envelope or window.
It is highly desirable to obtain a single isotope from a distribution of isotopes that are enriched. It is further desirable to provide a photochemical isotope separator which can be used to obtain a single isotope from a distribution of isotopes that are enriched, without causing anywhere in the apparatus a buildup of enriched material which might impede radiation.